Metodología científica para Cirugía Vascular. Estudios analíticos experimentales. El ensayo clínico / Experimental analytical studies. The clinical trial

Como hemos comentado anteriormente en un artículo previos, los estudios analíticos son aquellos en los que hay grupos de comparación que nos permiten el estudio de asociación de factores de estudio con eventos finales o resultados, como por ejemplo el tabaquismo y el desarrollo de AAA. En este artículo trataremos los estudios analíticos experimentales o, simplemente experimentales ya que podemos considerar que siempre los experimentales son analíticos al existir 2 grupos de comparación, por ejemplo, supervivencia de 2 tipos diferentes de tratamiento. (AU)

As we have previously discussed in a previous article, analytical studies are those in which there are comparison groups that allow us to study the association of study factors with final events or outcomes, such as smoking and the development of AAA. In this article, we will analyze the experimental analytical studies or, simply, experimental ones, because we can consider experimental studies to be analytical by nature, given the presence of 2 comparison groups, for example, the survival rates of 2 different types of treatment. (AU)

Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts.

OBJECTIVE: To analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG. MATERIAL AND METHODS: A retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed. STATISTICAL ANALYSIS: Survival analysis was performed for time-to-event data to assess patency. RESULTS: Group A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups. Technical and clinical success were 100% in group B and 94.5% and 91% respectively in group A. Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% y 15.7% respectively. Group B: 100%, 85.9%, 76,4% (p < 0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% y 31.3% respectively. Group B 100%, 95.3%, 95.2% (p < 0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 IC 95% 1.146-6.216, p = 0.010). CONCLUSION: A higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion.

Resultados del tratamiento endovascular de la estenosis de la anastomosis venosa en las fístulas arteriovenosas protésicas para hemodiálisis de PTFE. Análisis comparativo entre fístulas permeables y trombosadas / Results of endovascular treatment of venous anastomotic stenosis in prosthetic arteriovenous for hemodialysis PTFE grafts. Comparative analysis between patent and occluded grafts

Objetivo: Analizar los resultados del tratamiento endovascular (TEV) de las estenosis en las anastomosis venosas (EAV) de las fístulas arteriovenosas protésicas (FAVp), comparando su utilidad al realizarse sobre FAVp permeables frente a trombosadas.Material y métodosEstudio retrospectivo de pacientes intervenidos mediante TEV por EAV de fístulas humeroaxilares realizadas entre enero de 2009 y diciembre de 2019 en nuestro centro. Grupo A: FAVp trombosada secundaria a EAV; Grupo B: FAVp permeable con EAV detectada en seguimiento. Se definió éxito técnico como estenosis residual ≤ 30% y éxito clínico como diálisis efectiva inmediata. Tras el TEV se realizó un seguimiento clínico y con eco-Doppler semestral. Estudio estadístico: se realizó un análisis de supervivencia mediante el método Kaplan Meier para el estudio de permeabilidades.ResultadosGrupo A: 55 pacientes. Grupo B: 22 pacientes. No existieron diferencias significativas en las características demográficas ni anatómicas entre grupos.El éxito técnico y clínico fueron del 100% en el grupo B frente a un 94,5% y 91%, respectivamente, en el grupo A.La permeabilidad primaria a 1, 6 y 12 meses en el Grupo A fue: 81,8%, 22,4% y 15,7%, respectivamente, frente al Grupo B: 100%, 85,9%, 76,4% (p<0,001). Permeabilidad secundaria a 1, 6 y 12 meses en el Grupo A fue 85,2%, 45,8% y 31,3%, respectivamente, frente al Grupo B 100%, 95,3%, 95,2% (p<0,001). El uso de stents no cubierto se asoció a un mayor riesgo de oclusión (HR 2,669 IC 95% 1,146-6,216, p=0,010).ConclusiónEs esperable una mayor permeabilidad del TEV realizado sobre una FAVp permeable, por lo que es recomendable elaborar programas de seguimiento que sean capaces de detectar la EAV previo a su trombosis. (AU)

Objective: To analyze the results of endovascular treatment of venous anastomotic stenosis (VAS) in humero-axillary arteriovenous grafts (HAG), comparing outcomes between patent and thrombosed HAG.Material and methodsA retrospective cohort study was made of endovascular treated patients because of a VAS in a HAG between January 2009 and December 2019. Group A: Thrombosed HAG secondary to a VAS. Group B: Patent HAG with a VAS detected during follow-up. Technical success was defined as residual stenosis after treatment <30%, and clinical success as satisfactory immediate dialysis after surgery. After ET a biannual clinical and ultrasound follow-up was performed. Statistical analysis: Survival analysis was performed for time-to-event data to assess patency.ResultsGroup A: 55 patients. Group B: 22. There were no significative differences in demographic and anatomical factors between groups.Technical and clinical success were 100% in Group B and 94.5% and 91% respectively in Group A.Primary patency at 1, 6 and 12 months was: Group A: 81.8%, 22.4% and 15.7% respectively. Group B: 100%, 85.9%, 76.4% (p<0.001). Secondary patency at 1, 6 and 12 months was: Group A: 85.2%, 45.8% and 31.3% respectively. Group B 100%, 95.3%, 95.2% (p<0.001). Use of non-covered stents was associated with an increased risk of occlusion (HR 2.669 95% CI 1.146–6.216, p=0.010).ConclusionA higher patency of EV performed on a patent HAG is expected. It is therefore advisable to develop surveillance programs that are capable to detect VAS before its occlusion. (AU)

¿Cómo interpreto un metaanálisis publicado en una revista científi ca? / How to understand a meta-analysis in a medical journal?

El objetivo del estudio es evaluar el resultado de las estatinas sobre diferentes aspectos de los AAA. Fijémonos quela frase anterior recoge la esencia ya comentada del metaanálisis: sintetizar con cocina estadística los resultadosde diferentes diseños para sacar una única conclusión

The aim of the study is to assess the outcome of statins on diff erent aspects of AAAs. Note that the above sentencecaptures the essence of meta-analysis: synthesising the results of diff erent designs with statistical studies to drawa single conclusion

Aortic Rupture by an Acute Dissection of the Thoracoabdominal Aorta in a 12-Year-Old Boy.

Aortic dissection is exceptional in children. When they are affected, many clinical conditions as Marfan syndrome or Ehlers-Danlos syndrome are usually involved, but up to 22% have no associated background. Its high morbidity and low incidence in this age group require a high level of suspicion in children without predisposing factors when the presentation is atypical, to avoid the severe consequences of the delay of their diagnosis. In this article we describe the dissection and aortic rupture in a 12-year-old child without relevant medical history, and the open repair that was performed as treatment.

Pseudoaneurisma micótico carotídeo. Presentación de un caso clínico y revisión de la literatura / Carotid mycotic pseudoaneurysm. Case report and review

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Comparison of popliteal artery aneurysm therapies.

OBJECTIVE: Surgical treatment of popliteal artery aneurysms (PAAs) has advanced over time. Constant development of new endovascular techniques has converted these into the most attractive methods available today. However, results for each endovascular procedure are still limited, and available data have emerged from studies examining only a small number of cases. The present retrospective review was designed to examine early and late results for PAA treatment and to identify possible factors associated with graft patency. METHODS: This was a retrospective review of all PAAs treated from January 1993 to December 2013. Symptomatic and asymptomatic PAAs >2 cm treated using open surgery or an endovascular procedure were included. Kaplan-Meier curves and the Breslow test were used to analyze data. RESULTS: A total of 171 aneurysms were treated in 142 men (mean age, 69.3 years); of these, 53.3% were asymptomatic and 18.7% presented as acute ischemia. Saphenous vein was used for bypass in 57.9% of the patients, expanded polytetrafluoroethylene (ePTFE) in 23.4%, and a stent graft in 18.7%. In the open surgical group, a popliteal-popliteal bypass was performed in 37.4% and a distal anastomosis to a tibial vessel was required in 14.4%. Good runoff (two to three vessels) was present in 69%. Perioperative mortality (30 days) was 1.8%. Of eight early occlusions recorded, five (2.9%) underwent reoperations. Major amputations were needed in five patients (all with previous acute ischemia). Median follow-up for the entire cohort was 49 months (range, 1-228 months). Primary and secondary patency rates at 24, 36, and 60 months were 76.3% and 89.5%, 73.4% and 87.4%, and 68.3% and 80.9%, respectively. Popliteal-popliteal bypasses showed better primary patency at 24 months when saphenous vein was used vs ePTFE (94.9% vs 79%; P = .04); however, similar patency rates were recorded for short ePTFE bypasses and stent grafts (79% vs 79.7%). On multivariate analysis, only poor runoff emerged as an independent factor for worse primary patency (hazard ratio, 3.5; 95% confidence interval, 1.7-7.2; P = .001). CONCLUSIONS: The open repair of PAA offers good long-term results, especially in asymptomatic patients, those undergoing elective surgery, and those showing good runoff. Given the also good midterm outcomes of endovascular treatment, this may be a feasible option in selected patients.

Treatment with amlodipine and atorvastatin has additive effect on blood and plaque inflammation in hypertensive patients with carotid atherosclerosis.

Since previous studies have reported a beneficial effect of amlodipine and atorvastatin treatment in experimental atherosclerosis, we aimed to investigate the effect of the combination of both drugs on blood and plaque inflammation in patients with carotid stenosis. For that purpose, twenty six hypertensive patients undergoing carotid endarterectomy were randomized to receive either atorvastatin 20 mg/day alone (ATV, n=12) or in combination with amlodipine 20 mg/day (ATV+AML, n=14) before scheduled carotid endarterectomy. At the end of follow-up (4-6 weeks), there was a significant decrease in total and LDL-cholesterol levels, but not in blood pressure levels. In contrast, decreased MCP-1 plasma levels, NF-kappaB activation (EMSA) and MCP-1 mRNA expression (quantitative PCR) was only observed in blood from ATV+AML treated-patients. Moreover, carotid atherosclerotic plaques from ATV+AML group demonstrated a significant reduction in macrophage infiltration in relation to ATV group (immunohistochemistry). Our results suggest that combined treatment with atorvastatin and amlodipine decreases inflammatory status of atherosclerotic patients more than atorvastatin treatment alone, suggesting that co-administration of both drugs could have beneficial additive effects.

[Peripheral artery disease: pathophysiology, diagnosis and treatment]. / Enfermedad arterial periférica: aspectos fisiopatológicos, clínicos y terapéuticos.

Peripheral artery disease is one of the most prevalent conditions, and it frequently coexists with vascular disease in other parts of the body. Early diagnosis is important for improving the patient's quality of life and for reducing the risk of serious secondary vascular events such as acute myocardial infraction (AMI) or stroke. The best noninvasive measure for identifying the presence of occlusive arterial disease is the ankle-brachial index, which can also be used to indicate the prognosis of the affected extremity and to predict the likelihood of AMI during follow-up. Intermittent claudication in the lower limbs is the most common clinical presentation. The presence of critical ischemia (i.e., with rest pain or trophic changes) indicates the need for prompt revascularization because of the high risk of limb amputation. The more proximal the affected arterial segment, the better the outcome of the procedure. Endovascular treatment is usually reserved for lesions affecting multiple segments. It gives poorer results in occluded arteries. In extensive disease, conventional surgery is usually the best option.

Enfermedad arterial periférica: aspectos fisiopatológicos, clínicos y terapéuticos / Peripheral artery disease: pathophysiology, diagnosis and treatment

La enfermedad arterial periférica (EAP) es una de las afecciones más prevalentes y es habitual la coexistencia con enfermedad vascular en otras localizaciones. El diagnóstico precoz es importante para poder mejorar la calidad de vida del paciente y reducir el riesgo de eventos secundarios mayores, como el infarto agudo de miocardio (IAM) o el ictus. El mejor test no invasivo para diagnosticar la presencia de EAP es el índice tobillo-brazo que, además, tiene valor pronóstico para la extremidad afectada y para el desarrollo de IAM durante el seguimiento. La claudicación intermitente de los miembros inferiores es la forma más frecuente de presentación clínica. La presencia de isquemia crítica (dolor en reposo o lesiones tróficas) implica la necesidad de tratamiento de revascularización precoz, por el elevado riesgo de pérdida de la extremidad. El pronóstico del procedimiento realizado es mejor cuanto más proximal sea el sector arterial afectado. El tratamiento endovascular se reserva habitualmente para las lesiones más segmentarias y tiene peor resultado en las oclusiones arteriales. En lesiones más extensas, la cirugía convencional suele ser la mejor alternativa (AU)

Peripheral artery disease is one of the most prevalent conditions, and it frequently coexists with vascular disease in other parts of the body. Early diagnosis is important for improving the patient's quality of life and for reducing the risk of serious secondary vascular events such as acute myocardial infraction (AMI) or stroke. The best noninvasive measure for identifying the presence of occlusive arterial disease is the ankle-brachial index, which can also be used to indicate the prognosis of the affected extremity and to predict the likelihood of AMI during follow-up. Intermittent claudication in the lower limbs is the most common clinical presentation. The presence of critical ischemia (i.e., with rest pain or trophic changes) indicates the need for prompt revascularization because of the high risk of limb amputation. The more proximal the affected arterial segment, the better the outcome of the procedure. Endovascular treatment is usually reserved for lesions affecting multiple segments. It gives poorer results in occluded arteries. In extensive disease, conventional surgery is usually the best option (AU)

Validación del eco-Doppler carotídeo como diagnóstico único de la estenosis carotídea extracraneal / Validation of Doppler ultrasound as the only diagnosis of extracranial carotid stenosis

Introducción. En los últimos años ha crecido el interés por indicar la endarterectomía carotídea basada en eco-Doppler, por lo que es imprescindible la validación continuada de los laboratorios hemodinámicos de los servicios de Cirugía Vascular. Objetivos. Presentar la concordancia del eco-Doppler frente a una prueba de referencia en los pacientes remitidos a nuestro laboratorio. Identificar el grupo de pacientes en los que la exactitud del eco-Doppler podría emplearse como prueba de diagnóstico único preoperatoria. Pacientes y métodos. Se estudian 47 pacientes (94 carótidas) con sospecha de enfermedad carotídea significativa en pacientes remitidos a nuestro laboratorio. En todos se realiza prueba de referencia de control (arteriografía: 78,7%; angiorresonancia: 21,3%). Resultados. Se ha obtenido en el total de la serie un coeficiente kappa de 0,89 dúplex-prueba de referencia. Se detectaron 10 oclusiones, que se confirmaron con pruebas de referencia. Las curvas COR (serie global) para la velocidad sistólica (VS), velocidad diastólica (VD) y ratio VS carótida interna/común (VSI/VSC) presentaron las áreas 92,7, 93,4 y 90,5%, respectivamente. Se han establecido como puntos de corte de estenosis grave los siguientes: VS: 275 cm/s (sensibilidad: 93,3%; especificidad: 88,9%); VD: 90 cm/s (sensibilidad: 90%; especificidad: 94,4%) y ratio VSI/VSC: 3,5 (sensibilidad: 90%; especificidad: 85,2%). La validez del eco-Doppler mejora cuando se excluyen los pacientes con estenosis grave u oclusión contralateral (COR VS: 97,2%; VD: 97,7%; ratio VSI/VSC: 92,5%). En el diagnóstico de estenosis grave con contralateral levemoderada, el valor kappa ha sido 0,95. Conclusiones. El dúplex carotídeo es una prueba fiable y válida en el diagnóstico de la estenosis carotídea extracraneal. Puede utilizarse como diagnóstico preoperatorio único cuando el eje carotídeo contralateral no presente enfermedad grave y el estudio sea de buena calidad

Introduction. In recent years there has been growing interest to indicate Doppler ultrasound-based carotid endarterectomy, which thus makes continual validation by the haemodynamic laboratories in Vascular Surgery services essential. Aims. Our aim was to present a comparison of DU versus a reference test in patients referred to our laboratory. We also sought to identify the group of patients that allowed the precision of Doppler ultrasound to be used as a single preoperative diagnostic test. Patients and methods.We studied a sample of 47 patients (94 carotids) who were referred to our laboratory with suspected significant carotid diseases. A control reference test was carried out in all of them (arteriography: 78.7%; MR angiography: 21.3%). Results. A duplex-reference test kappa coefficient of 0.89 was obtained for the whole series. Ten occlusions were detected, which were confirmed with reference tests. The ROC curves (overall series) for the systolic velocity (SV), diastolic velocity (DV) and the internal/common carotid SV ratio (ISV/ CSV) presented areas of 92.7, 93.4 and 90.5%, respectively. The following cut-off points for severe stenosis were established: SV: 275 cm/s (sensitivity: 93.3%; specificity: 88.9%); DV: 90 cm/s (sensitivity: 90%; specificity: 94.4%) and the ISV/CSV ratio: 3.5 (sensitivity: 90%; specificity: 85.2%). The validity of Doppler ultrasound is improved when patients with severe stenosis or contralateral occlusion are excluded (ROC SV: 97.2%; DV: 97.7%; ISV/CSV ratio: 92.5%). In the diagnosis of severe stenosis with mild-moderate contralateral stenosis, the kappa value was 0.95. Conclusions. Carotid duplex is a reliable, valid test for diagnosing extracranial carotid stenosis. It can be used as a single preoperative diagnosis when the contralateral carotid axis does not present any serious disease and the study is of sufficiently high quality

Modulación mediante tratamiento con atorvastatina y/o amlodipino del perfil de proteínas liberadas por placas ateroscleróticas humanas / Modulation of the profile of proteins released by human atherosclerotic plaques through

Introducción. Entre las diversas estrategias seguidas para analizar la compleja estructura de la placa de ateroma, nuestro grupo se ha centrado en el estudio de las proteínas secretadas por la pared vascular, que podrían ser potenciales marcadores plasmáticos. Las estatinas o los agentes bloqueadores de los canales de calcio (BCC) pueden modular los valores de las proteínas circulantes en sujetos con diversas afecciones cardiovasculares. Métodos. La electroforesis bidimensional y la espectrometría de masas (EM) se han aplicado al estudio de proteínas diferencialmente secretadas por placas de ateroma incubadas ex vivo respecto a zonas fibrosas adyacentes. Asimismo, hemos estudiado el efecto modulador de la atorvastatina (10­5 M), el amlodipino (10­6 M) o la combinación de ambos fármacos. Resultados. De una media de 620 proteínas detectadas por gel, se identificaron en total 83 proteínas secretadas por las placas ateromatosas mediante EM: 34 proteínas incrementadas en los sobrenadantes de las placas cultivadas ex vivo respecto a las zonas control y 31 con valores de secreción inferiores en la zona ateromatosa. La adición in vitro de fármacos a las placas de ateroma produjo diferentes efectos en los valores de secreción proteicos, dependiendo del tipo de fármaco y de la proteína considerada, si bien la mayoría de las proteínas identificadas revertía a valores control independientemente del tratamiento. Conclusión. Mediante este análisis proteómico hemos caracterizado nuevas proteínas potencialmente involucradas en la formación e inestabilidad de la placa de ateroma. La modulación por distintos tratamientos farmacológicos de dichos marcadores puede ayudar a comprender nuevos mecanismos de acción de dichos fármacos (AU)

Introduction. Analysis of the complex structure of the atheroma plaque is a classical object of cardiovascular research. We studied proteins secreted by the vascular wall, which could be potential plasma markers. Statins or calcium channel blockers modulate the levels of different circulating proteins in patients with diverse cardiovascular diseases. Methods. Two-dimensional electrophoresis and mass spectrometry were applied to identify and characterize proteins differentially secreted by atheroma plaque samples incubated ex vivo versus adjacent fibrous segments considered as controls. We also analyzed the modulatory effect of atorvastatin (10­5 M), amlodipine (10­6 M) and the combination of both drugs. Results. From an average of 620 proteins detected per gel, a total of 83 proteins secreted by atheroma plaque samples were identified by mass spectrometry: 34 proteins were increased in atheroma plaque supernatants versus control segments while 31 showed decreased secretion levels in atheroma plaques. Different effects were detected after in vitro drug administration to complicated atheroma plaques, depending on the kind of drug and protein considered, although the majority of the proteins identified reverted to normal levels independently of the treatment administered. Conclusion. Proteomic analysis characterized a significant number of novel proteins potentially involved in the formation and instability of complicated atherosclerotic plaques. Modulation of these markers by different drugs may help us to understand new potential mechanisms through which these drugs exert their beneficial effects on atherothrombosis (AU)

Sustitución protésica en los aneurismas de aorta torácica / Prosthetic replacement in thoracic aortic aneurysms

Objetivo. Revisar el estado actual de la cirugía de sustitución protésica de la aorta en los aneurismas de la aorta torácica. Desarrollo. Se repasan la historia natural, las indicaciones de cirugía y la selección de los pacientes para la intervención. Se revisan la monitorización anestésica, la clasificación anatomoquirúrgica y los aspectos relacionados con la técnica como el abordaje, la exposición de la aorta y el implante de la prótesis aórtica. Se realiza una revisión de los métodos adjuntos utilizados en la clínica para prevenir la paraplejía postoperatoria. Finalmente se exponen los resultados contemporáneos de los grupos con mayor experiencia. Conclusiones. A pesar del gran impacto que el tratamiento endovascular está obteniendo en la comunidad quirúrgica, para algunos pacientes la cirugía de sustitución protésica puede ser la mejor o la única alternativa de tratamiento. La intervención debe realizarse en centros con experiencia, y se deben seleccionar los métodos complementarios adecuados según la extensión del aneurisma y las características clínicas de cada paciente. El uso de perfusión aórtica distal junto con el drenaje del líquido cefalorraquídeo posiblemente sea el método más apropiado para aquellos pacientes con aneurismas en los que sea previsible un tiempo de clampaje aórtico prolongado

Aim. To review the current state of the art of surgical prosthetic replacement in thoracic aorta aneurysms. Development. The natural history, indications for surgery and selection of patients for the intervention are also considered. The article deals with anaesthetic monitoring, anatomical-surgical classification and aspects related to the technique, such as the approach, exposure of the aorta and placement of the aortic graft. The adjunctive methods used in clinical practice to prevent post-operative paraplegia are also reviewed. Finally, we report on the results currently being obtained by the groups with the longest experience. Conclusions. Despite the great impact endovascular treatment is having on the surgical community, for some patients prosthetic replacement surgery may be the best or the only therapeutic alternative. The intervention should be carried out in centres with experience in such procedures and suitable complementary methods must be chosen according to the size of the aneurysm and the clinical characteristics of each patient. The use of distal aortic perfusion together with cerebrospinal fluid drainage may be the most appropriate method for patients with aneurysms where prolonged aortic clamping is expected

Disease progression in the contralateral carotid artery after endarterectomy.

Our objectives were to establish the incidence and progression of stenotic lesions in the contralateral carotid artery (CCA) after endarterectomy, to identify subpopulations of patients at risk of contralateral disease progression, and to evaluate the efficacy of duplex scanning surveillance at detecting these lesions. We performed a prospective study on 180 patients in whom the CCA to the operated artery was healthy or showed <70% stenosis. All patients had completed a clinical and hemodynamic follow-up program, including duplex scanning of both carotids, with sessions 3 and 6 months after surgery and then every semester until 2 years. Thereafter, examinations were scheduled according to the severity of stenosis. Mean follow-up time was 26.2 months (range 1.6-67.6). Disease progression was observed in 26 lesions (15%), nine of which (5.5%) progressed to severe stenosis (SS). Kaplan-Meier event-free rates of any disease progression were 89%, 88%, 82%, and 79% for 1, 2, 3, and 4 years, respectively. Event-free rates of progression to SS were 98%, 96%, 93%, and 90.6%, respectively, for 1, 2, 3, and 4 years. The risk of progression to SS was five times higher for stenoses that were moderate at the start of the study (p = 0.025). Severe contralateral stenoses were more common and appeared later during follow-up than ipsilateral restenoses. Progression of contralateral stenotic lesions is not uncommon and is essentially related to the presence of a moderate lesion at the start of follow-up. Indeed, moderate stenosis is a risk factor for progression to SS, which appears later and more frequently than ipsilateral restenosis. It therefore seems that patients with a moderate contralateral lesion would benefit from long-term duplex ultrasound surveillance.